Colloquium announcement

Faculty of Engineering Technology

Department Production Technology
Master programme Mechanical Engineering

As part of his / her masterassignment

Coen Hartjes

will hold a speech entitled:

Development of an interface strength characterization method for overmolded thermoplastic composites

RoomHR N109


Overmolding of thermoplastic composites is a hybrid process that combines the stamp forming and injection molding process. It is well suited for automated large series production of complex parts with excellent structural performance, a high level of function integration and allows for net shape manufacturing. One of the challenges that prevents widespread adoption by the industry is the uncertainty regarding the interface strength between the laminate and injected polymer.

The interface bond is developed by the diffusion of polymer chains across the interface, this process is called healing. Characterizing and predicting the interface strength is essential in order to use the overmolding process for structural parts.

In this research, several requirements for a proper interface strength characterization method are drawn up. Characterization methods found in literature were rated according to these requirements and it was found that there are no adequate methods available. Therefore, two interface characterization methods were developed according to the requirements: a short beam 3 point bending and a V-shape 4 point bending method. These methods were applied to characterize the interface strength of overmolded C/PAEK V-shapes for different insert temperatures before overmolding. The experimental results were similar to those found in literature. It was, therefore, concluded that the methods show potential to be used for interface strength characterization. It was found that the specimen quality, material parameter prediction and thermal stresses have an influence on the accuracy of the characterization methods. Further research is, therefore, needed in those areas.